Programmatically waking up HDMI? -- Possible?

  1. Is it possible to programmatic-ally wake up the HDMI interface?
  2. When the HDMI is “asleep” or “suspended”, is audio still available in the chip’s I2S inputs?

I2S discussion on a another thread got me playing with embedded application media (mainly sound) things. Initial investigation is using a TV connected via HDMI, but I would probably want to experiment with an I2C DAC later.

Unfortunately, in truly embedded applications with no USB mouse or keyboard attached, there is a problem with getting the HDMI interface to wake up.
I’d like to be able to kick something with a python script to do this, or disable suspend all together.

If the I2C data is still active on the input of the HDMI framer chip while said chip is asleep, this issue might be a non-problem for my end game…



For the normal console, you can disable blanking with:

  setterm -blank 0

...or wake up a blanked console via:

  setterm -blank poke

There are some other setterm settings (powerdown, powersave) you might
have to mess with as well.

There is a similar utility for raw X called xset, and many of the
display managers (ie: gnome, kde) have their own way of setting up
screen blanking and power-save.

- --
Charles Steinkuehler